In recent times, much research and development effort has been devoted to creating new and useful devices for dispensing drugs to a needy drug receptor site. Generally, these devices deliver drug by diffusion from a non-erodible polymer matrix, by release from an erodible polymer matrix, or by delivery from an osmotic device. While these prior art devices are useful for their intended purpose, serious shortcomings are associated with their use. For example, devices which contain drug dispersed or dissolved in a non-erodible matrix often do not exhibit zero order drug release kinetics since the drug is first removed only from the surface layers of the matrix and the distance the drug must diffuse to the surface from within the matrix increases with time. For this kind of device, essentially t.sup.-1/2 kinetics are observed, with accompanying drug delivery declining over time. A serious shortcoming for devices made from an erodible polymer is the polymer's inability to dissolve or erode at a uniform rate over time. Correspondingly, for these devices, drug is not delivered to the receptor at a uniform rate over time. One shortcoming observed for osmotic devices is the need for the drug to be soluble in fluid imbibed into the device, since a drug that cannot act as its own osmotically effective solute will not imbibe fluid, and without imbibition, the drug is not pumped from the device. In view of the above presentation, it will be appreciated by those versed in the art that a critical need exists for a drug delivery device that is simple in construction, easy to make, and can dispense drug at a controlled rate over a prolonged period of time to an animal drug receptor site.